Device consisting at least of two parts joined together

ABSTRACT

Two parts which form a device and are joined together according to the related art are joined in a complex manner and require additional elements to produce a tight joint.  
     A device ( 1 ) is described which has two parts ( 3, 6 ), has welding pockets ( 9 ) which are capable of receiving material during the welding operation for producing a joint.

FIELD OF THE INVENTION

[0001] The present invention is directed to a device.

BACKGROUND INFORMATION

[0002] Joining two parts by a threaded joint is generally known. Thus,for example, an insertion probe of a device for determining a parameterof a medium flowing in the duct is placed in a duct at least partiallyby being screwed onto a wall of the duct. In addition, further sealingelements such as rubber rings for example must be present on theinsertion probe to seal the duct outward. Screwing in is an additionalprocess step after the installation of the insertion probe in the duct.In addition, a further component, namely the sealing element, must beinstalled. Such a device is shown in U.S. Pat. No. 5,804,718, forexample.

SUMMARY OF THE INVENTION

[0003] The device according to the present invention has the advantageover the related art that a joint, which is moisture- and air-tightwithout additional means, is easily established between two parts.

[0004] The presence of welding pockets when two parts are weldedtogether is advantageous, because material from at least one of theparts enters the welding pocket and is thus unable to affect the joiningprocess between the two parts. In addition, the material which flows oris deformed during the welding operation cannot reach the environmentbecause it is held in the welding pocket.

[0005] The at least one welding pocket may advantageously be present onone or on both parts. Furthermore, the interaction of the two parts mayalso result in the formation of an advantageous welding pocket.

[0006] It is advantageous if a second part has a first projection, onwhich the first part rests during welding, because a defined weldingpocket which produces a tight joint between the parts is thus produced.

[0007] It is advantageous if the parts are joined by orbital vibrationwelding, because this method subjects the parts and/or componentssituated on the parts to less thermal and mechanical stress compared toultrasound welding. Thus, for example, a heat-sensitive and/orvibration-sensitive electronic component may be placed on at least onepart before the welding operation without being damaged by the weldingoperation.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008]FIG. 1 shows a first exemplary embodiment of a device designedaccording to the present invention.

[0009]FIG. 2a shows another exemplary embodiment of a device designedaccording to the present invention.

[0010]FIG. 2b shows another exemplary embodiment of a device designedaccording to the present invention.

[0011]FIG. 3 shows a device designed according to the present inventionhaving a first projection.

[0012]FIG. 4a shows a device designed according to the present inventionhaving a second projection.

[0013]FIG. 4b shows a device in which the two parts are welded together.

DETAILED DESCRIPTION

[0014]FIG. 1 shows a first part 3 and a second part 6 of a device 1designed according to the present invention.

[0015] The two parts 3, 6 are welded together.

[0016] Device 1 has, for example, a duct forming second part 6 and aninsertion probe 3 forming first part 3, which is inserted into the ductthrough an insertion opening 7, at least one parameter of a mediumflowing in the duct being determined using a sensor in insertion probe3. Such a device is known, for example, from German Patent Application198 27 375 A1 and should be part of this disclosure.

[0017] Parts 3, 6 are made, for example, but not necessarily, of plasticand have a central axis 21, for example. One axial end 4 of first part 3is designed with a T-shaped cross section, for example. First part 3 issituated at least partially in second part 6, for example, and rests onsecond part 6, part 6 having a tubular design in the area of T-shapedend 4 of part 3.

[0018] In a radial direction 27 between first part 3 and second part 6,there is a distance d different from zero, whereby a cavity acting as awelding pocket 9 is formed between first part 3 and second part 6.

[0019] During the welding operation, material may be eroded from orpressed off at a contact surface 33 between T-shaped end 4 of first part3 and second part 6. This material enters the at least one weldingpocket 9 and no longer interferes with the welding operation betweenfirst part 3 and second part 6.

[0020] Vibration welding, in particular orbital vibration welding, whichis based on friction heating and plasticizing of parts 3, 6 in the areaof contact surface 33, by may be used as the welding process. It iscarried out via a unidimensional, oscillating or biaxial relative motionhaving adjustable amplitudes of 0.25 to 2.5 mm and frequencies between80 and 300 Hz, for example, under a simultaneously acting pressure ofP=0.5 to 8.0 MPa exerted perpendicularly to contact surface 33.

[0021]FIG. 2a shows an additional exemplary embodiment of a device 1designed according to the present invention.

[0022] Welding pocket 9 is formed, for example, only on second part 6 byintroducing a depression in an inner wall 10 of second part 6 in theproximity of contact surface 33 to form welding pocket 9.

[0023] This depression to form welding pocket 9 may also be only onfirst part 3 in an outer wall 11 in the proximity of contact surface 33(FIG. 2b). Distance d in the radial direction between first part 3 andsecond part 6 may then be zero or very small.

[0024]FIG. 3 shows an additional exemplary embodiment of a device 1designed according to the present invention.

[0025] Second part 6 has a first projection 12, which extends in theaxial direction, i.e., runs parallel to central axis 21 and has contactsurface 33 at an axial end. First projection 12 extends centrally, forexample, from a base surface 22 of part 6.

[0026] Welding pocket 9 is delimited in radial direction 27 by firstprojection 12 and an outer wall 11 of first part 3, which is oppositefirst projection 12 in radial direction 27. In axial direction 21,welding pocket 9 is delimited by base surface 22 of part 6 and the Thead of axial end 4 of part 3.

[0027] The space facing outward in radial direction 27 of firstprojection 12 also forms a welding pocket 9.

[0028]FIG. 4a shows an additional exemplary embodiment of a device 1designed according to the present invention.

[0029] Second part 6 has a second projection 15, which is situated onthe outer radial edge of second part 6, i.e., on the outside oppositefirst projection 12 in radial direction 27 and extends in axialdirection 21. Contact surface 33 of second part 6 with first part 3 isformed on first projection 12 and not on second projection 15. Duringthe welding operation, the axial end of first projection 12 and firstpart 3 in the area of contact surface 33 are heated and plasticized, sothat material 18 enters welding pockets 9 radially inward and outward.

[0030] Part 18 of first projection 12 which is deformed is identified bycross-hatching.

[0031]FIG. 4b shows the two parts 3, 6 of a device 1 designed accordingto the present invention when welded together.

[0032] Contact surface 33 forms a sealing surface 24 against air andmoisture.

[0033] Second projection 15 of second part 6 may, but does not need to,rest on first part 3 and prevents material 18, which is present in outerwelding pocket 9, from escaping out of outer welding pocket 9 to theoutside.

What is claimed is:
 1. A device, in particular a device for determiningat least one parameter of a medium flowing in a duct, comprising atleast two parts which are joined together, wherein the parts (3, 6) arewelded together, and at least one welding pocket (9) is present, whichis capable of receiving material (18) of the at least one part (3, 6)that is displaced when the two parts (3, 6) are welded together.
 2. Thedevice as recited in claim 1, wherein at least one part (3, 6) has atleast one welding pocket (9).
 3. The device as recited in claim 1,wherein the at least one welding pocket (9) is formed by two parts (3,6).
 4. The device as recited in claim 1, 2, or 3, wherein a second part(6) has a first projection (12) on which the first part (3) rests. 5.The device as recited in one or more of the preceding claims, wherein atight joint (24) exists between the parts (3, 6) due to the welding. 6.The device as recited in one or more of the preceding claims, whereinthe parts (3, 6) are welded together by vibration welding, in particularorbital vibration welding.
 7. The device as recited in one or more ofthe preceding claims, wherein the first part (3) is situated at leastpartially in the second part (6); and the second part (6) has a secondprojection (15) which surrounds the welding spot (24) in the radialcircumferential direction (27).
 8. The device as recited in claim 6,wherein the first part (3) has a heat-sensitive and/orvibration-sensitive electronic component.